(a) Field of the Invention
The present invention relates to welding methods of tin balls, and particularly to a electric connector and IC tin ball shaping and fixing manufacturing method.
(b) Description of the Prior Art
Conventionally, electric connectors, CPUs, chips, zero insertion electric connector or electric elements are welded to a circuit board. A plurality of terminals embedding holes are punched on a circuit board for embedding a plurality of terminals. Then the terminals are welded and fixed by tin material. This way is not preferred for terminals with a larger number of pins and with slender pins. Therefore, it is not adapted in the current electronic technology. To improve the defects in the prior art, the bottom of the terminals are combined with tin balls which are then welded to a circuit board.
However, the tin balls are adhered to a circuit board by various ways, for example, the welding portion of a terminal is formed with two copper clips or FIGS. 10 and 11, the welding portion 101 of a terminal 10 is formed as a plane and welding assisting agent 102 is sued in welding (referring to FIG. 12). Therefore, the manufacturer must prepare several producing lines for these tedious works so that the costs in manufacturing and repair are high. Moreover, the forms of the terminals are fixed and can not be designed as desired.
For the manufacturing method that the plan welding portion of a terminal 10 is combined with melted tin ball 20 using welding assisting agent (referring to FIGS. 10 and 11), the welding portion 101 of the terminal 10 has a plane structure so that the welding assisting agent can be printed upon the welding portion 101. If the welding portion has a needle shape or an embedded shape, the welding portion is not suitable for printing the welding assistant agent. Therefore, the prior art is not a preferred way and can not be used in various terminal structure.
Accordingly, the primary object of the present invention is to provide an electric connector and IC tin ball shaping and fixing manufacturing method used in welding portions of terminals of one of an electric connector, IC and other electronic elements so that the terminal can be welded to the tin balls of the ball grid array seat. The manufacturing method comprising: select a ball grid array seat, wherein the internal of the ball grid array seat has been embedded with terminals and a bottom of each terminal has a terminal welding portion; covering a tin film on a bottom of the ball grid array seat; wherein the tin film is formed by connecting a plurality of round small tin pieces with respect to the terminals, and a periphery of the small tin pieces being enclosed by slender connecting portions; thermally melting the ball grid array seat covered by the tin film so that the small tin pieces of the tin film melt as tin liquid, then the slender connecting portions will breaks and the small tin pieces are connected as a tin ball or like a tin ball; thereby, the liquid tin ball will enclose the welding portion of the terminal; and cooling and condensing the tin balls and then combining the tin balls to the welding portions at the bottoms of the terminals of the ball grid array seat.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.